Adjusting driver stage output impedance

Details Adjusting driver stage output impedance Adjusting driver stage output impedance

2006-02-28

2008-11-04

Tabler, Matthew C. (Department: 2819)

Electronic digital logic circuitry

Signal sensitivity or transmission integrity

Bus or line termination

Reexamination Certificate

active

07446557

ABSTRACT:
In order to generate a control signal for adjusting a driver stage with an adjustable output impedance, an impedance signal is generated for a measure of the output impedance of the driver stage. The difference between the impedance signal and a reference signal is calculated, and passed to a sigma-delta modulator to generate a digital bitstream signal. The control signal is then generated depending on the bitstream signal, where the frequencies of the two signal states in the bitstream signal are evaluated by means of digital counters. Depending on the difference of the determined frequencies of the two signal states, a counter is increased or reduced, and the control signal is generated depending on the count of the counter. The impedance signal may be generated by a replica circuit of a pull-up region or a pull-down region of the driver stage to be adjusted.

REFERENCES:
patent: 5606275 (1997-02-01), Farhang et al.
patent: 6307424 (2001-10-01), Lee
patent: 6414512 (2002-07-01), Moyer
patent: 6703908 (2004-03-01), Ruesch et al.
patent: 6750796 (2004-06-01), Holloway et al.
Maxim [Hrsg.], “A Simple ADC Comparison Matrix,” Application Note 2094; Jun. 2, 2003, Maxim Integrated Products Inc., Sunnyvale CA 90486, pp. 1-3.

Affiliated with

Also associated with

Rating

Adjusting driver stage output impedance does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Adjusting driver stage output impedance, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Adjusting driver stage output impedance will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-4038575